Definitions of star grass:

• noun:   any plant of the genus Hypoxis having long grasslike leaves and yellow star-shaped flowers: Africa; Australia; southern Asia; North America
• noun:   perennial Australian grass having numerous long spikes arranged like the vanes of a windmill
• noun:   any of several perennials of the genus Aletris having grasslike leaves and bitter roots reputed to cure colic
• noun:   trailing grass native to Europe now cosmopolitan in warm regions; used for lawns and pastures especially in southern United States and India